Question

Passage:
In 1908, Norwegian physicist Kristian Birkeland published his extensive investigation into the origins of the aurora borealis, basing his conclusions on experiments with a "terrella"—a magnetized metallic sphere suspended in a vacuum chamber. By directing beams of cathode rays (electrons) toward the magnetized sphere, Birkeland successfully replicated visual rings of light surrounding the sphere's magnetic poles, mirroring the auroral ovals observed in Earth's polar atmospheres. Birkeland hypothesized that the solar atmosphere continually ejected energetic electrons into space, which were then channeled by Earth's magnetic field toward the polar regions to produce auroral displays. Although mainstream geophysicists of his era, notably Lord Kelvin and Sydney Chapman, rejected Birkeland's theory on the grounds that continuous particle streams would be dissipated by electrostatic repulsion prior to reaching Earth, satellite observations in 1967 ultimately confirmed the presence of electric currents—now designated Birkeland currents—flowing along geomagnetic field lines into the ionosphere.

According to the passage, which of the following statements about Birkeland's experiment or hypothesis are explicitly supported? Select all that apply.